Vehicle-spring



2 Sheets- Sheet l.'

l (No Mdel) VBHNLE SPRING.

Patented Mar. 22, 1887.

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2 Sheets-Sheet 2.

(No Model.)

J. D. FURNAS. VEHICLE SPRING. No. 359,719. Patented Mar. 22, 1887.

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VEHICLE-SPRING.

SPECIFICATIQN forming pari: of Letters Patent No. 359.719, dated March 22. 1837.

Application tiled September 17, 1385. Serial No. 177,398. (No model.)

To @ZZ whom it may concern.-

Be it known that I, JOHN D. FUnNAs, of lVaynesville, county of Varrcn, State of Ohio, have invented certain new and useful improvements in Springs for Vehicles` tc., of which the following is a full and exact description, reference being had to the accompanying drawings, making part ot' this specification.

My invention relates to that class of springs for vehicles in which the saine is spirally wound, and my invention consists in a novel construction ot' spring made in trapezoidal forni in crosssection, having the two sides or angies formed on lilies drawn or radiating troni the axial center to the exterior circumference thereof".

It further consists in a novel construction of blocks by which the springs are connected to the vehicle-body and running-gear, having grooves or threads formed therein, one side of which is cut or formed on an incline, adapt-ing it to the increased pitch of the spring caused by its insertion therein, and having the other side formed or inclined to the normal pitch of the spring, whereby the spring will hold itself connected to the block.

It further consists iu the combination, with the vehicle body and running-gear, ot'an extensible spirally-wound spring rigidly attached at its upper end to the running-gear and at its lower end to the body of the vehicle.

It further consists in the combination, with the spirally-wound spring, of divided spil-allygrooved blocks and means for clamping said blocks together and to the spring, and to certain details in the construction and arrangenient of parts, all as hereinafter described.

In the accompanying drawings, Figure 1 is a side view of au entire spring when not at tension, showing blocks connected thereto at each end, by which it may be attached to the vehicle and running-gear. Fig. 2 is a side view of the saine, showing the spring as elongated hy the application of a weight acted upon hy the vertical force of gravity only. Fig. 3 is a side view of the saine, showing the position of the spring at a tension which is caused by the application of a weight in a diA rection parallel with the resultant of vertical I and lateral forces while both ends and their attachments, being rigidly connected, are held.

Fig. el is a top view of the block and bolts by which the spring may he held and secured to the vehicle or running-gear. Figs. 5 and G are side views of the blocks having a portion of the screw-th read or groove formed in each, and in and between which the end of the spring is clamped. Figs. 7, S, and 9 are, respectively, top, side, and end views showing the application ofthe device to a side-bar vehicle. Figs. l0, 1l, and l2 are, respectively, top, end, and side views showing the application of the spring to a vehicle in which a vertical support passes up within the coil of the spring and attached rigidly to the upper end thereof, while the weight or load is connected to the lower end; and Fig. 13 shows a cross-section of the wire of the spring o, representing the axial center of the spring. Fig. 14: is a side view ofa portion cfa spring, showing the same connected with its holding-block; and Fig. l is a view ofthe holding-block,showing the form of the groove therein for receiving the end of the spring.

The springs S are iliade of wire, in trape zoidalA form Vin cross-section, and may he` of any size, width, or pitch, as may be desired.

In Fig. 13 a crosssection of the spring is shown, which l. believe to he the most perfect forni, and in which gure is also illustrated to some extent the method ot determining the proper form of any wire, no matter what its size or what the diameter of the coil, and in which o represents the axis of the coil, O H the radins of its outside, and o t the radius of its inside, a d the inner edge, and c e the outer edge, the two sides or angles of which are formed on lines drawn or radiating from the axial center to the exterior circumference.

It may be shown experimentally that the strength of coils of spiral springs is 'inversely as their distances from their axes-that is, inversely as their radii. Any coil may he rcgarded as made up of a great nuinloer of very minute coils joined together as one. A crosssection of one of these minute imaginary coils may be regarded as apoint; hence the strength of any point in a coil so made up is inversely as its distance from the rEhen will the strength he equal at points equally distant from the axis. The width of a cross-section remaining the saine, the strength of a wire is proportional to its thickness. Then, in order to maintain a uniform strength at every distance from the axis of coilto be constructed,the thickness must vary directly as the distance. Then the required thickness will be to the known `thickness as the distance from the axis to the point at which it is desired to ascertain the thickness is to the distance from the axis to the point where the thickness is known.

Then let equal the required thickness, a the knownlthickness, b the l'ormer distance, and@ thelat-terdistancc, then x aub c; hence x:

ab 6. By constructing according to tlns formula a cross-scction,cach portion of thc wire will bei as able to withstand rupture as another, and no useless material is employed.

The spring thus fornied is connected at each end to blocks W. These blocks may be made either in one or two parts, and where` made in two parts a portion of the thread or groove is cut in each, and. the two parts are held together by nieans of screws or bolts b b. The threads or grooves are formed in the blocks in such manner that a portion of the` groove is formed to the normal pitch of the spring and-inclines upward gradually on an ineline corresponding to the increased pitch of thespring caused by its insertion in tliegroove, the normal. pitch being from a point, as, to a point, x', and the increased pitch from a point,

', to a point, rc2, which construction of grooveI causes the spring to engage the inclined faces ofthe groove and hold the spring engaged with the block. One of these blocks is connected to the runninggear and the other to the body of the vehicle-or' that is, the upper end of the spring is connected to the runninggear and the lower end to the body in a vertical position.

By connecting the spring rigidly and only at its ends to the body and running-gear great freedom of movement is obtained without undue strain upon the spring. i

Having now described my invention, I claim- I l. Aspring for vehicles made in trapezoidal forni in cross-section, the two sides or angles of` which are formed on lines drawn or radiating from the axial center to the exterior circumference thereof, as set forth.

2. A spirally-wound spring for Vehicles made in substantially trapezoidal form in cross-section, the outer parallel side of whichs is to the inner parallel side as the radius or distance from the axis of the spring to the outer side is to the radius or distance from the v same axis to theinncr side, as set forth.

3. The blocks by which the springs are con-l nected to the body and run ning-gear, having grooves or threads formed therein, substantially as described-that-is, one portion ot' which is cut or formed on an incline correspending to the normal pitch ofthe spring and the other portion on an increased incline or pitch corresponding to the increased pitch,

of the spring caused by its insertion thereinas and for the purpose set forth.

et. The combination,with the body and running-gear of a vehicle, of the spirally-wound` vertically-arranged spring connected rigidly and only at its upper and lower ends to the body and runninggear, as set forth.

5. The combina-tion of the spirally-wound spring, the blocks made in two parts, withia portion of the thread formed in each, and;

means, substantially as described, for holding the portions ot the blocks together, as set forth.`

JOHN D. F URNAS.

Vi tnesses:

PETER SELLERS, Hownnn Horiiins. 

